Java API的问题输出为空。只有来自intelliji

我的程序输出为空。我不知道为什么。当我在Firefox中输入请求时，一切都很好

我猜原因可能是输出代码中的“数组”手镯“[]”

public class Connect {

    public String connect() {
        String  output = null;

        try {
            URL url = new URL("http://aviation-edge.com/v2/public/flights?key=[key]=3");
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setRequestProperty("Accept", "application/json");

            if (conn.getResponseCode() != 200) {
                throw new RuntimeException("Failed : HTTP Error code : "
                        + conn.getResponseCode());
            }
            InputStreamReader in = new InputStreamReader(conn.getInputStream());
            BufferedReader br = new BufferedReader(in);
            output = br.readLine();
            System.out.println(output);
            br.close();

        } catch (Exception e) {
            System.out.println("Exception in WeatherApi:- " + e);
        }
        return output;
    }

}

Firefox的输出--->

---

请帮助我，我累了。

我已经修改了你的程序，请检查此代码。它现在正在工作。你错过了while条件

public String connect() {
    String output = null;
    String key = "679820-995fb7";

    try {
      String connectUrlString =
          "http://aviation-edge.com/v2/public/flights?key=" + key + "&limit=3";
      System.out.println("URL String : " + connectUrlString);
      //      URL url = new URL("http://aviation-edge.com/v2/public/flights?key=[key]=3");
      URL url = new URL(connectUrlString);
      HttpURLConnection conn = (HttpURLConnection) url.openConnection();
      conn.setRequestMethod("GET");
      conn.setRequestProperty("Accept", "application/json");

      if (conn.getResponseCode() != 200) {
        throw new RuntimeException("Failed : HTTP Error code : " + conn.getResponseCode());
      }

      BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
      String inputLine;
      StringBuffer response = new StringBuffer();

      while ((inputLine = in.readLine()) != null) {
        response.append(inputLine);
      }
      in.close();
      output = response.toString();
    } catch (Exception e) {
      System.out.println("Exception in WeatherApi:- " + e);
    }
    return output;
  }

---

我已经修改了你的程序，请检查此代码。它现在正在工作。你错过了while条件

public String connect() {
    String output = null;
    String key = "679820-995fb7";

    try {
      String connectUrlString =
          "http://aviation-edge.com/v2/public/flights?key=" + key + "&limit=3";
      System.out.println("URL String : " + connectUrlString);
      //      URL url = new URL("http://aviation-edge.com/v2/public/flights?key=[key]=3");
      URL url = new URL(connectUrlString);
      HttpURLConnection conn = (HttpURLConnection) url.openConnection();
      conn.setRequestMethod("GET");
      conn.setRequestProperty("Accept", "application/json");

      if (conn.getResponseCode() != 200) {
        throw new RuntimeException("Failed : HTTP Error code : " + conn.getResponseCode());
      }

      BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
      String inputLine;
      StringBuffer response = new StringBuffer();

      while ((inputLine = in.readLine()) != null) {
        response.append(inputLine);
      }
      in.close();
      output = response.toString();
    } catch (Exception e) {
      System.out.println("Exception in WeatherApi:- " + e);
    }
    return output;
  }

---

当我在google chrome中调用这个url时，我得到{“error”：{“text”：“Invalid API KEY”}。您是否已将密钥保存在firefox中？您好，没有http是正确的，我已隐藏密钥：）firefox的输出只是一个示例。我只是想说，java可能认为“[]”之前是数组。我不知道如何退出。您必须以编程方式在请求中传递隐藏密钥。我知道！：）我只在堆栈溢出上隐藏了密钥。这是完整的请求。现在我的输出是“[”。当我在google chrome中调用这个url时，我得到了{“错误”：{“文本”：“无效的API密钥”}。你在firefox中保存了密钥了吗？嗨，没有http是正确的，我有隐藏的密钥：）firefox的输出只是一个例子。我只是想说java可能认为“[]”之前是数组。我不知道如何退出它。你必须以编程方式在请求中传递隐藏键。我知道！：）我这里只有堆栈溢出的隐藏键。这是完整的请求。现在我的输出是“[”。。